Saralasin and SQ 20881 : their effects on central nervous system norepinephrine

The effects of the infusion of Saralasin and SQ 20881, two drugs that inhibit the renin-angiotensin system, on the norepinephrine (NE) concentration in hypothalamus and medulla oblongata were studied in male Wistar rats. NE content increased in hypothalamus in response to both drugs, without changes in medulla oblongata catecholamine concentration. These results showed that the NE concentration of certain areas of the central nervous system can be modified, in a short time, by the inhibition of the renin-angiotensin system. Results observed after the infusion of Saralasin could indicate that the receptors, on which the angiotensin acts to produce this alteration, are similar to those of the peripheral blood vessels.